Cups vs. Grams: Why Weighing Ingredients Gives Better Results
By the Kindly Useful team, updated 2026-11-05
If the same recipe sometimes turns out perfect and sometimes dry and dense, measuring is the likely cause. Cups measure volume; grams measure weight. For liquids that hardly matters, but for flour, sugar and anything that packs, it can change the result completely.
Why a cup of flour isn't a fixed amount
Flour compacts. Scoop a measuring cup straight into the bag and you may get 150-160 g. Spoon the flour into the cup and level it with a knife and you get about 120-125 g. Sifted, it can drop to 110 g. That's a difference of up to 40%, the difference between a tender cake and a brick.
Weight doesn't care how the flour was handled: 125 g is 125 g.
Not all cups are the same size
| Measure | Volume |
|---|---|
| US cup (customary) | 236.6 ml |
| US "legal" cup (nutrition labels) | 240 ml |
| Metric cup (Australia, NZ, Canada, South Africa) | 250 ml |
| UK imperial cup (old recipes) | 284 ml |
| US tablespoon | 14.8 ml |
| Australian tablespoon | 20 ml |
| Teaspoon (almost everywhere) | 5 ml |
The Australian tablespoon is the sneaky one: it's 4 teaspoons, not 3.
Ingredients that are fine by volume
Water, milk and most thin liquids weigh roughly 1 g per ml, so volume is accurate enough. Granulated sugar and salt don't compress much, so they're more forgiving than flour, but weighing is still faster and avoids washing measuring cups.
Ingredients you should weigh
- Flour of any kind, the biggest offender
- Brown sugar, which depends heavily on how firmly it's packed
- Cocoa powder and powdered sugar, which are light and fluffy
- Chopped nuts, chocolate chips and dried fruit, where pieces leave gaps
- Butter, if the recipe gives sticks or cups and you buy it in blocks
Butter conversions
In the US, butter comes in sticks: 1 stick = 1/2 cup = 8 tablespoons = 113 g. Most other countries sell 250 g or 200 g blocks, so a scale makes American recipes easy.
How to convert a recipe
- Find the weight per cup for each specific ingredient. There's no single cup-to-gram number, because a cup of honey weighs nearly three times as much as a cup of cocoa.
- Multiply by the amount in the recipe (1/2 cup, 3/4 cup and so on).
- Write the grams into the recipe so you never have to convert again.
Our kitchen converter does this for more than 60 ingredients, with tables for common amounts.
Get a scale
A digital kitchen scale costs about as much as a set of good measuring cups. Use the tare button: put the bowl on, press tare, add the first ingredient, press tare again, add the next. Fewer dishes and better results.